Organic phosphorus compoundbearing lubricant



Patented Nov. 24, 1942 oncmc PHOSPHORUS comron'rmnmmo LUBRICANT Bert n.Lincoln and Gordon D. Byrkit, Ponca City,

Okla., assignors to Continental Oil Company,

Ponca City, Okla., a corporation of Delaware No, Drawing. ApplicationMarch 14, 1940,

Serial No. 323,959

9 Claims.

This invention relates to improvements in lubricants. More specifically,this invention relates to improved materials which, when added tolubricants, greatly increase their resistance to oxidation and formationof corrosive products during use and often improves othercharacteristics as well. This application is a continuation-inpart ofour copending application, Serial No. 231,362, filed September23, 1938.

Present-day mechanical devices require lubriyeating oils of high filmstrength, of high oiliness characteristics, and of low tendency tooxidize during use. It has been found that the presentday hydrocarbonlubricants of the very highest quality are deficient in these veryimportant characteristics. These three properties are of vitalimportance under conditions of thin time in which the rubbing surfacesmust operate under conditions of dry friction if ordinary hydrocarbonlubricants are used. With dry friction, the wear on friction surfaces isextreme; and during cold weather when the lubricant is sluggish orduring periods when the lubricating system is not functioning properlyfor one reason or another, rubbing surfaces may not only sufferconsiderable wear but may be damaged to the point where they must bereplaced. The product of our invention has a very important property ofreacting with the metal surfaces, penetrating or adsorbing on filmlubrication where the lubricant has been squeezed from between thefriction surfaces because of high pressure, slow speeds, and othercauses. It is readily seen that the viscosity or the body of thelubricant plays no part in this type of lubrication and that theremaining film of oil must have a very high film strength and be of highoiliness value to prevent rupture of the film of the lubricant, whichwould cause seizure. The oil film must tend to keep the coeficient offriction as low as possible. The oil must resist oxidation when thesethin films are heated in the presence of oxygen as they are in use.

Mechanical devices are being designed for higher pressure operation, andthe film strength of the best quality straight hydrocarbon lubricant hasbeen found to-be too low. It will be obvious that an invention whichprovides a means of improving the film' strength of these lubricants isof The sludge is not a lubricant in any sense of the word, and thesoluble acid is particularly corrosive to bearing metals such ascadmium-silver, copperlead, and the like.

In starting idle mechanical equipment which is lubricated from a sump bypumping or circulating the lubricant, there is always a short period ofterious under conditions of thin film lubricationlj the metal surfaces,and leaving a film of lubricant with high oiliness character, whichremains on the metal surface irrespective of the length of time themachine has been idle.

This high oiliness film gives very even and smooth operation, which maybe easily discerned by the experienced operator or lubricating engineer.

When the hydrocarbon lubricants are diluted with unburned fuel or withother light hydrocarbons, the small degree of oiliness of the originalhydrocarbon lubricant is greatly decreased. We have found that theaddition of the products of our invention to hydrocarbon lubricants morethan compensates for the loss in oiliness and loadcarrying ability fromdilution.

It is well known that, in order to obtain lubricants which arepreeminently satisfactory from the standpoint of oxidation in use, it isnecessary to refine the oil thoroughly and then to add an inhibitor ofoxidation. The thorough refining may consist of more and heavier acidtreatments or solvent treating so as to remove a considerable part ofthe oil and leave only the most stable portion. Such drastic refining isnecessary in order to obtain stability with respect to sludge formation,but the oil is then subject to easy oxidation to form soluble acids andother corrosive materials. This can be prevented by the addition to therefined oil of small amounts of materials which either prevent theformation of these corrosive products or by some action render theminert. Furthermore, such well refined oils are susceptible to theformation during use of lacquerlike materials which tend to stick rings.This results in blow-by and hence loss of power, failure of lubrication,scratching, scoring, overheating, and. eventually replacement of parts.It

" r is practically impossible to refine a. lubricant in such a manner asto avoid all three of these dimculties, namely, sludge, solublecorrosive products,

' and lacquer.

It is considerably more advantageous to add the materials of ourinvention and avoid these difliculties by this method.

Many'of these additive materials are effective an added to poorlyrefined or even wholly unned lubricants. The addends may thus bestituted in. whole or in part for the usual ning processes. 11 the priorart of applying these principles to manufacture of lubricants, manydiverse es of materials have been suggested to be led to obtainimprovement in various chareristics. It has been found that the additionvarious organic esters of the oxygen and sulacids of phosphorusfrequently improves film ength, oxidation resistance, non-corrosiveness,:1 other characteristics. Nitrogen compounds ve been found to inhibitoxidation of oils. Our ,terials combine both of these properties. )neobject of our invention is to provide imived inhibitors of oxidation andcorrosion for clition to lubricants. Another object of our invention isto provide n strength improving addition agents suitable use inlubricants and especially in crankcase iricants. Other and furtherobjects of our invention i1 appear in the course of the following de--iption. in general, our invention consists of the ad- .ion of certainorganic phosphorus compounds staining at least one phosphorus-nitrogenuble bond to hydrocarbon fuels and lubricants. lese materials combinethe advantages of the osphorus compounds and of the nitrogen mpounds,particularly in preventing the delopment of corrosive materials duringuse. mpounds having a double bond between a iosphorus and a nitrogenatom have outstandg anti-oxidant properties. Why this is so is it clear,but the fact remains that it is so. We lieve that the anti-oxidantactivity is a relt of the augmented chemical reactivity at the 'int ofthe double bond, which is instrumental reducing to an unusual degree theoxidation .te and oxidation tendencies of the fuels and bricants w thwhich these compounds are ended. With a double bond between the nitronand phosphorus atoms, there is a likelihood at these may react withprimary valence bonds an oxidation reaction, thus showing more iemicalactivity than when all of the valences the n trogen and phosphorus atomsare satis- .d by primary valence bonds. Obviously we do at wish to bebound by these theories but only v the appended claims interpreted asbroadly the prior art permits.

Besides the unexpected and unusual oxidation mibiting effects producedby this class of comounds, there is increased film strength and inreasedoiliness. Some of these materials which re suitable for use inaccordance with our inention are shown in the following outline. A11 ndeach of these are to be considered as exmples of our invention whenblended in an oil f lubricating viscosity.

i. Phosphazo halides, R.-N:PX (R is an aromatic radical; X is a halogen)l. Phosphazobenzene chloride, CsHsNzPcl 2. Phosphazoxylene chloride,

(CH3) zcsHaNzPcl 3. Phosphazochlorobenzene chloride,

C1CeH4N2PC1 4. Phosphazophenylbenzene chloride,

. C6H5C6H4NIPC1 Phosphazonitrobenzene bromide,

O2NCsH4N:PBr

B. Aryloxy-Phosphazo-aromatics RNzPOR' (R and R are aromaticradicals) 1. Phenoxy-phosphazobenzene,

CsHsN Z POCoHs 2. p-Amyloxyphenoxy-phosphazobenzene.

CcHsN I POCsH4OC5H11 3. p-Amylphenoxy-phosphazobenzene,

CeH-sNzPoCsHicsHu 4. p-Amylphenoxy-phosphazotoluene,

CH3CcH4N 2 POCsH4C5H11 C. Anilides of phosphazo-aromatics RNzRNHR' (Rand R are aromatic radicals) 1. Phosphazobenzene anilide,

C6H5N2P.NHC6H5 2. Phosphazotoluene mesidide,

CH3CsI-I4N I P.NHCeH2 (CH3) 3 3. Phosphazochlorobenzene chloroanilide,

CICGH4NZRNHCBH4C1 D. Oxyphosphazo-aryl anilides, RNHPOENR' (R and R arearomatic radicals) 1. Oxyphosphazobenzanilide,

CsHsNHPOZNCaHs 1 2. Oxyphosphazobenzophenylanilide,

CsHsNHPO: NCsH4CuH5 3. Oxyphosphazochlorobenzotoluidide,

CH3CsH4NH.PO I NCeH4Cl 4. Oxyphosphazobenzochloroanilide,

C1CsH4NH.PO I NCoHs E. Trichlorophosphanils, RN:PC13 (R is an aromaticradical) 1. Trichlorophosphanil, csHsNzPCla 2.Trichlorophosphochloranil,

C1CsH4N=PC13 F. Sulfophosphazoaryl chlorides, RNzPSCl (R is an aromaticradical) 1. Sulfophosphazobenzene chloride,

C6H5NIPSC1 2. Sulfophosphazomethylbenzoate ride CHaO.CO.CsH4NtPSC1 3.Sulfophosphazochloronaphthalene chloride, ClCmHsNZPSCl G. Triarylphosphazines, RzC:N.N:PR'a (R is aliphatic; R is aromatic oraliphatic) 1. Tribenzyl phosphazine,

CH2 N.N:P(CH2CaH5) a 2. Tri-o-chlorobenzyl dimethylphosphazine (CH3) 2CN.N:P (CHzCuHiCl) a 3. Tricyclohexyl phosphazine,

CH2:N.NIP(CsHn)3 H. Aryl phosphin-imines, R3P=NR' (R' is aromatic, R'smay be aromatic or aliphatic) 1. Phenyl diethyl phenylphosphin-imine,

(CsHs) (C2H5)2PINC6H5 2. Triamyl phenylphosphin-imine, v (CsH11)3P:NCsH53. Tribenzyl o-chlorophenylphosphinimine (CsHsCI-Ia) 3PZNC6H4C1 Any ofthese compounds or other members of the classes represented or theirderivatives within the limitations set forth above may be used withinthe scope of our invention.

It is to be understood that in practicing our invention, oil-solublephosphorus-nitrogen compounds of the type described are to be selected.Some of the examples described have only limited solubility inhydrocarbon oils. It is to be remembered, however, that, because oftheir great efiiciency, extremely small amounts are often effective.Thus we may use as little as 0.001 per cent of some of these compounds,and it will be chloseen that a fairly insoluble material may dissolve toa sufllcient extent to be satisfactory for our purpose. In general, morethan 0.001 per cent of our addition agents are used, and we may add 7manent suspens n.

. .stearate, aluminum stearate, calcium: soaps of" Many of the moredifilcultly soluble materials are rendered more soluble by theintroduction of alkyl groups, particularly those containing four or morecarbon atoms. The isoamyl, octyl, lauryl, and octadecyl radicals andradicals from paraffln wax greatly increase the solubility of organiccompounds in oil. One or more of such groups may be introduced asrequired into the previously described compounds or their derivatives.For example, phosphazobenzanilide is not very soluble in hydrocarbonlubricating oils but phosphazooctadecyl-benzenexylidide is much moresoluble.

The selection of a particular compound or com-- pounds to be used as anaddition agent to the hydrocarbon oil is to be made considering the useto which the blend is put. Thus, if water is likely to be present duringuse, a phosphorus compound or combination of compounds is selected whichis not aflected by water. In general, we prefer to use compounds havingboiling points over 250 F. It is sometimes advantageous 'to combine morethan one of these compounds in a blend to obtain particular properties.We accomplish this by mixing two or more of these compounds together andblending the mixture with the hydrocarbon oil or by blending one in thehydrocarbon oil, blending the second into this mixture, and so on untilthe composition is complete.

The various phosphorus-nitrogen compounds usually improve both the filmstrength and oxidation characteristics of the hydrocarbon oil. Forexample, th sludging tendencies may be decreased by as little as 0.001per cent of our phosphorus-nitrogen compounds. The oxidationcharacteristics of lubricants are very important, and these are markedlyimproved by our compounds. The ability to reduce friction is anotherfeature contributed to lubricants by our phosphorus-nitrogen compounds.

It may be desirable to include in one and the same blend based on ahydrocarbon oil, in addition to the iaddends here described, otheraddends for specific purposes. Thus, we may add a pour point depressorsuch as a naphthalenechlor wax condensation product and a viscosityindex improver such as certain resins or polymerized hydrocarbons inaddition to our organo-phosphorus compounds. Furthermore. variousmetallic compounds may be added to the blend without interfering withthe action of our ingredients. Indeed, in some cases it is advantageousto combine with our organic phosphorus-nitrogen compounds in a h droarbon oil blend such materials as calcium d chlorostearate, chromiumoleate, tin octadecyl phthalate, aluminum stearate, and other metallicsoaps.

Our addends are admirably adapted for use Example 1 Per centMid-Continent paraffin-base SAE 30 99. 0 p-Amylphenoxyphosphazobenzene1.0

Example 2 Per cent California naphthenic base SAE 30 99. 5Phosphazo-p-tert.-butylbenzene anilide 0. 5

Example 3 Per cent Mid-Continent mixed base SAE 50 98. 4 Aluminumnaphthenate 1. 3 Tribenzyl phosphazine 0. 3

Example 4 Per cent Mid-Continent paraiiin base SAE 40 93. 8 Voltolizedcorn oil 5. 0 Chlorodiphenylene oxide 1.0 Triamyl phenylphosphin-imine0. 2

Example 5 In making a grease containing our addends. we may use:

Per cent Oleic acid 8. 1 Lime 1. 2 Water 0. 3 Dichlorosteari'c acid 1. 1Bright stock 13. 1 Distillate (440 seconds at 100 F.) 76. 0Phosphazobenzene chloride 0.2

Example 6 In making a lubricating gasoline, we blend 0.5 per cent of theproduct of Example 1 with gasoin lubricating oils of all types includingthose designed for use in automotive crankcases, Diesel oils, and anyother oils of lubricating viscosity such as castor oil, cottonseed oil,lard oil, sperm oil, shale oil. Furthermore, .our addends areadvantageously blended in gasoline and other petroleum fuels eitherdirectly or after being blended first in a lubricating oil and thenadded to the fuel. Soap-thickened mineral oils of all types ranging fromthose showing only a slight increase in viscosity over that of themineral oil alone to the semisolid and solid greases containing fiftypercent or more of soap are amenable to treatment according to ourinvention. In making these greases, the usual soaps such as sodium betafat and the like may be used. Various other thickening ingredients ormaterials for other purposes may be added. These include yarn, hairgraphite, glycerol, water, lamp black, mica, zinc dust, litharge, and.the like.

The following examples of blends of our additon agents are given asillustrations but not as limitations:

line. The product has the composition:

Per cent Gasoline 99.5 Oil 0.495 p-Amlyphenoxyphosphazobenzene 0.005

It is to be understood, however, that the hydrocarbon oil in the treatedfuels may be of a viscosity of from about 35 seconds at F. S. S. U. to350 seconds'or more; and the amount of oil blended with thephosphorus-nitrogen compound to form the fuel addend may vary between 0per cent and 99.5 per cent. In some cases the fuel may be preparedwithout adding any hydrocarbon oil. Th quantity of phosphorous-nitroencompound in the final blended fuel may ary from 0.0001 to 1.0 per centor slightly more.

It will be understood that certain features and ubcomblnations may beemployed without reirence to other species or combinations. This scontemplated by and is within the scope of ur claims. It is furtherobvious that various :hanges may be made in details within the scope itour claims without departing from the spirit )1 our invention. It istherefore to be under- ;tood that our invention is not to be limited ;6the details described.

Having thus described our invention,.we claim:

1. A lubricant comprising in combination a najor proportion of oil oflubricating viscosity and a minof proportion of an organic phosphorussompound containing at least one nitrogenphosphorus double bond.

2. A lubricant comprising in combination a majo proportion of oil oflubricating viscosity and a minor proportion of an organic compoundcontaining phosphorus and nitrogen connected by a double bond.

- 3. A lubricant comprising in combination oil of lubricating viscosityand from 0.001 to 5 per cent of an organic phosphorus compoundcontaining at least one nitrogen-phosphorus double bond.

4. A lubricant comprising in combination a major proportion of oil oflubricating viscosity and a minor proportion of a phosphazine.

5. A lubricant comprising in combination a major proportion of oil oflubricating. viscosity and a minor proportion of a phosphazo-aromaticanilide.

6. A lubricant comprising in combination a major proportion of oil oflubricating viscosity and a minor proportion of anaryloxyphosphazoaromatic.

7. A lubricant comprising in combination a major proportion of oil oflubricating viscosity and a minor proportion of p-Amylphenoxy-phosorphazotoluene.

8. A lubricant comprising in combination a major proportion of oil oflubricating viscosity and a minor proportion of phosphazobenzeneanilide.

9. A lubricant comprising in combination a major proportion of oil oflubricating viscosity and a minor proportion of tribenzyl phosphazine.

BERT H. LINCOLN. GORDON D. BYRKIT.

